Wideband is a term used in communication systems to describe a signal or channel that has a broad frequency range. Some synonyms for wideband may include "broadband," "wide-frequency," or "wide-range." These terms refer to the same concept of a signal that is capable of transmitting a large amount of data or information over a wider range of frequencies than a narrowband signal. In addition to these synonyms, other related terms such as "high-speed," "high-bandwidth," or "large-capacity" can also be used to describe a wideband signal or channel. Overall, the use of these synonyms emphasizes the importance of a signal's capacity for carrying large amounts of information quickly and efficiently.